The main objective of this paper is to present an approach to
identify active faults in karstic enviroments. This is achieved by
a releasing relationship between sinkholes or dolines formation,
array and active faults mechanism. In this research , Lar
valley on the Northeast of Tehran, Capital of Iran was selected
as a case study. The sinkholes array in the valley shows that their
formation and location is influenced by active faults. As a result
of active faults mechanism, a number of young and old dolines
have been formed on north and south of the study area. According
to Aerial Photographs, Satellite images and geological
logs corelation three major active faults were distingushed in
the study area specially under Lar dam structure. Two of the
faults are elongated to the north and the one extends to the
south, seven sinkholes were formed on faults. Based on the
available evidences, it is assumed that the formation and array
of dolines in the study area has been formed and controlled by
active faults. Conversely , it is deduced that faults activity may
be determinated by sinkholes formation and array. This results
may be applied for the similar cases of world,s karstic belt.